Risk of cardiovascular adverse events from trastuzumab (Herceptin(®)) in elderly persons with breast cancer: a population-based study.

Randomized controlled trials have reported a 4-5 times increased risk of heart failure (HF) in breast cancer patients receiving trastuzumab (Herceptin (®) ) compared to patients who do not receive trastuzumab. However, data regarding the cardiac effects of trastuzumab on elderly patients treated in general practice remain very limited. Using the US surveillance, epidemiology, and end results (SEER)-Medicare database, we conducted a retrospective cohort study on the cardiac effects of trastuzumab use in all incident breast cancer patients diagnosed from 1998 to 2007 who were 66 years and older, had no prior recent claims for cardiomyopathy (CM) or HF, and were followed through 2009. We defined our outcome as the first CM/HF event after diagnosis. We performed Cox-proportional hazard models with propensity score adjustment to estimate CM/HF risk associated with trastuzumab use. A total of 6,829 out of 68,536 breast cancer patients (median age: 75) had an incident CM/HF event. Patients who received trastuzumab tended to be younger, non-white, diagnosed more recently, and had a stage IV diagnosis. Trastuzumab use was associated with an increased risk of CM/HF (HR = 2.08, 95 % CI 1.77-2.44, p < 0.001). The trastuzumab-associated CM/HF risk was stronger in patients who were younger (HR = 2.52 for 66-75 years and HR = 1.44 for 76 years and older, p < 0.001) and diagnosed in recent years (HR = 2.58 for 2006-2007 vs. 1.86 for 1998-2005, p = 0.01). The twofold risk of CM/HF associated with trastuzumab remained regardless of patients' diagnosis stage, presence of hypertension, cardiovascular comorbidities, or receipt of anthracyclines, taxanes, or radiation. Trastuzumab may double CM/HF risk among elderly breast cancer patients. Our findings reinforce the need to prevent and manage cardiac risk among elderly breast cancer patients receiving trastuzumab.

Potential increased risk of cancer from commonly used medications: an umbrella review of meta-analyses.

Several commonly used medications have been associated with increased cancer risk in the literature. Here, we evaluated the strength and consistency of these claims in published meta-analyses. We carried out an umbrella review of 74 meta-analysis articles addressing the association of commonly used medications (antidiabetics, antihyperlipidemics, antihypertensives, antirheumatics, drugs for osteoporosis, and others) with cancer risk where at least one meta-analysis in the medication class included some data from randomized trials. Overall, 51 articles found no statistically significant differences, 13 found some decreased cancer risk, and 11 found some increased risk (one reported both increased and decreased risks). The 11 meta-analyses that found some increased risks reported 16 increased risk estimates, of which 5 pertained to overall cancer and 11 to site-specific cancer. Six of the 16 estimates were derived from randomized trials and 10 from observational data. Estimates of increased risk were strongly inversely correlated with the amount of evidence (number of cancer cases) (Spearman's correlation coefficient = -0.77, P < 0.001). In 4 of the 16 topics, another meta-analysis existed that was larger (n = 2) or included better controlled data (n = 2) and in all 4 cases there was no statistically significantly increased risk of malignancy. No medication or class had substantial and consistent evidence for increased risk of malignancy. However, for most medications we cannot exclude small risks or risks in population subsets. Such risks are unlikely to be possible to document robustly unless very large, collaborative studies with standardized analyses and no selective reporting are carried out.

Bevacizumab use and risk of cardiovascular adverse events among elderly patients with colorectal cancer receiving chemotherapy: a population-based study.

BACKGROUND: Cardiovascular risk attributable to bevacizumab (Avastin(®), BEV) for treatment of metastatic colorectal cancer (CRC) remains unclear. We conducted a population-based cohort study to assess the safety of BEV use among patients aged ≥ 65. PATIENTS AND METHODS: We identified CRC patients diagnosed from 2005 to 2007 who received chemotherapy and were followed until 31 December 2009. Outcomes were 3-year risk of arterial thromboembolic events (ATEs), cardiomyopathy or congestive heart failure (CM/CHF), and cardiac death (CD) after chemotherapy initiation. We fitted Cox-proportional hazards (PHs) models with inverse-probability-of-treatment-weights and calculated hazard ratios (HRs) for the risk of adverse events. RESULTS: We identified 6803 CRC patients (median age: 73 years). Those with cardiac comorbidity were less likely to receive BEV (P < 0.0001). BEV is associated with an elevated risk of ATEs (HR = 1.82, 95% CI = 1.20-2.76, P < 0.001; rate difference: 3.5 additional cases/1000 person-years). We observed no association between BEV and CD or CM/CHF. CONCLUSIONS: In general practice, the cardiovascular risk of BEV in elderly CRC is modest. The observed ATEs risk is lower than reported in clinical trials, which may be due to careful patient selection. Our findings may facilitate clinical decision-making of BEV use in elderly patients.

The relation between projected breast cancer risk, perceived cancer risk, and mammography use. Results from the National Health Interview Survey.

BACKGROUND: Although the use of mammography on at regular intervals can save lives, not all women obtain the repeat mammography recommended in guidelines. OBJECTIVE: To assess the associations between routine mammography use, perceived cancer risk, and actual projected cancer risk. METHODS: We include women who were 45 to 75 years of age and who had responded to the 2000 National Health Interview Survey. Women who reported that they believed their risk of getting cancer in the future was "medium" or "high" were considered jointly as "medium/high-risk perception.""Routine mammography use" was defined as having > or =3 mammograms in the previous 6 years. We used logistic regression to determine the independent relation between cancer risk perception, projected breast cancer risk, and routine mammography use. RESULTS: Of the 6,002 women who met our inclusion criteria, 63.1% reported routine mammography use. About 76% of women in the highest quartile of projected breast cancer risk reported routine mammography use, compared with only 68%, 64%, and 51% in the third, second, and first quartiles, respectively (P<.001 chi-square test for trend). After adjusting for indicators of access to care, sociodemographic and behavioral factors, and perceived cancer risk, women in the highest quartiles of projected cancer risk were significantly more likely to report routine mammogram use than women in the lowest quartile (odds ratio [OR] of women in third and fourth quartiles were 1.57 [1.24 to 1.99], and 2.23 [1.73 to 2.87] vs the lowest quartile, respectively). Women with a higher perceived cancer risk were significantly more likely to undergo routine mammography (adjusted OR: 1.29 [1.12 to 1.48] P=.001). Cancer risk perceptions tended to be higher among women who were younger age, obese, smokers, depressed, or reported one of the following breast cancer risk factors: family breast cancer history, prior abnormal mammogram, and early age at menarche. CONCLUSION: Actual and perceived risk were independent predictors of routine mammography use, suggesting that efforts to incorporate risk profiles into clinical decision making may need to involve more than just relaying information about projected risks to patients, but also to explore how risk perceptions can be affected by this information.

Hereditary breast/ovarian and colorectal cancer genetics knowledge in a national sample of US physicians.

BACKGROUND: Clinically relevant genetics knowledge is essential for appropriate assessment and management of inherited cancer risk, and for effective communication with patients. This national physician survey assessed knowledge regarding basic cancer genetics concepts early in the process of introduction of predictive genetic testing for breast/ovarian and hereditary non-polyposis colorectal cancer (HNPCC) syndromes. METHODS: A stratified random sample was selected from the American Medical Association Masterfile of all licensed physicians. In total, 1251 physicians (820 in primary care, 431 in selected subspecialties) responded to a 15 minute questionnaire (response rate 71%) in 1999-2000. Multivariate logistic regression analyses were conducted to identify demographic and practice characteristics associated with accurate response to three knowledge questions. RESULTS: Of the study population, 37.5% was aware of paternal inheritance of BRCA1/2 mutations, and 33.8% recognised that these mutations occur in <10% of breast cancer patients. Only 13.1% accurately identified HNPCC gene penetrance as >or=50%. Obstetrics/gynaecology physicians, oncologists, and general surgeons were significantly more likely than general and family practitioners to respond accurately to the breast/ovarian questions, as were gastroenterologists to the HNPCC question. CONCLUSIONS: These nationally representative data indicate limited physician knowledge about key cancer genetics concepts in 1999-2000, particularly among general primary care physicians. Specialists were more knowledgeable about syndromes they might treat or refer elsewhere. Recent dissemination of practice guidelines and continued expansion of relevant clinical literature may enhance knowledge over time. In addition to educational efforts to assist physicians with the growing knowledge base, more research is needed to characterise the organisational changes required within the healthcare system to provide effective cancer genetics services.

US physicians' attitudes toward genetic testing for cancer susceptibility.

Genetic testing for an inherited susceptibility to cancer is an emerging technology in medical practice. Little information is currently available about physicians' attitudes toward these tests. To assess US physicians' opinions on unresolved issues surrounding genetic testing, a 15-min survey was administered to a stratified random sample of 1,251 physicians from 8 specialties, selected from a file of all licensed physicians in the US (response rate = 71.0%). Dependent measures included physicians' attitudes toward genetic counseling and testing qualifications, availability of guidelines, patient confidentiality and insurance discrimination issues, and clinical utility of genetic tests. More than 89% of physicians reported a need for physician guidelines, 81% thought that patients with positive genetic test results are at risk for insurance discrimination, and more than 53% thought that it was difficult to ensure the confidentiality of test results. Almost 25% indicated that genetic tests for cancer susceptibility have too many inaccurate or ambiguous results; nearly 75% thought that clear guidelines are not available for managing patients with positive test results. Only 29% of physicians reported feeling qualified to provide genetic counseling to their patients. More than 84% of oncologists considered themselves qualified to recommend genetic testing to their patients compared with 40% of primary care physicians (PCPs), and 57% of tertiary care physicians (TCPs). US physicians expressed great uncertainty about issues surrounding genetic testing for cancer susceptibility. Results of this national survey underscore the need to provide physicians with clear guidelines on the use of genetic cancer susceptibility tests and effective medical training on their appropriate implementation.

Expression of p27(Kip1) and bcl-2, cigarette smoking, and colorectal cancer risk.

Although a positive association between cigarette smoking and colorectal adenoma development is consistently found, the association with colorectal cancer remains controversial. We evaluated the potential roles of p27(Kip1) and bcl-2 protein expressions in conjunction with cigarette smoking exposure and colorectal cancer risk in a hospital-based case-control study. A total of 163 colorectal cancer patients from Roswell Park Cancer Institute and Buffalo General Hospital and 326 healthy controls responded to a standardized questionnaire on colorectal cancer risk factors including detailed information on their history of cigarette smoking; 110 of the patients' tumours were available for immunohistochemical analysis of p27(Kip1) and bcl-2 protein overexpression. An avidin-biotin immunoperoxidase procedure was used to determine expression after incubation with mouse monoclonal p27(Kip1) and mouse monoclonal bcl-2 antibodies, respectively. A statistically significant trend for total pack-years of smoking was found when p27(Kip1) positive cases were compared with p27(Kip1) negative cases (trend test, p = 0.007). Although a weak inverse association was observed with smoking exposure among p27(Kip1) negative tumour cases in comparison to controls, a significant dose-response association was seen with p27(Kip1) positive tumours. The relative risk of developing a p27(Kip1) positive tumour was estimated to be 1.17 (95% CI 0.54-2.54) for those with less than 20 pack-years, 1.95 (95 % CI 0.95-3.97) for those with 20-39 pack-years, and 2.25 (95% CI 1.14-4.45) for those with greater than 39 pack-years of smoking exposure (trend test, p = 0.009) when compared with controls. When cases with bcl-2 expression were compared with cases without bcl-2 expression, suggestion of a trend was also observed with pack-years smoked (trend test, p = 0.09). In our study of 110 patients with sporadic colorectal cancer and 326 controls, we observed differences in associations between cigarette smoking and expressions in p27(Kip1) and bcl-2. Our data suggest that bcl-2 overexpression (or a bcl-2 dependent pathway) is associated with cigarette smoking in the development of colorectal cancer, whereas a loss of p27(Kip1) expression is not. These associations indicate that there is aetiological heterogeneity in colorectal cancer development, and that they can indirectly allude to where these changes in protein expression occur in the adenoma-carcinoma sequence (i.e. early versus late events).

Prognostic significance of p53 and p21(waf1/cip1) immunoreactivity in epithelial cancers of the ovary.

OBJECTIVES: Theprognostic value of p53 expression in epithelial ovarian cancer remains unresolved. We hypothesized that prognosis may relate more to expression of p21(waf1/cip1), the major downstream effector of p53, which can also be induced through p53-independent mechanisms. We therefore studied the relationship of p53 and p21(waf1/cip1) expression in epithelial ovarian cancers to clinicopathological variables and prognosis. METHODS: Fixed, embedded tumors from 85 patients with untreated, primary epithelial ovarian cancer were immunostained with antibodies to p53 and p21(waf1/cip1). Expression was correlated with clinicopathological features and prognosis. Survival curves were calculated by the Kaplan-Meier method and compared using the log-rank test for p53, p21(waf1/cip1), and all combinations of expression of the two markers. RESULTS: Sixty-two percent of tumors expressed p53, and 42% expressed p21(waf1/cip1). There was no correlation between p53 and p21(waf1/cip1) expression. Advanced stage, grade, age >/=50, and p53 expression were associated with worse disease-free survival. Patients whose tumors were p53(+)/waf1(-), however, had a particularly strong association with poorer disease-free survival when compared with other combinations of p53 and p21(waf1/cip1) expression (P = 0.003). Neither p53, nor p21(waf1/cip1), nor combinations of expression were independently related to survival when histology, age, stage, and differentiation were considered. CONCLUSIONS: p53 expression in the absence of p21(waf1/cip1) expression is a better marker of poor prognosis than either p53 or p21(waf1/cip1) expression status alone in univariate analysis. Absence of independent prognostic significance may be related to the paucity of early stage cases in the current study.

Somatic alterations and metabolic polymorphisms.

Cancer is a multistep process in which multiple genetic alterations occur, causing a cumulative adverse effect on the control of cell differentiation, cell division and growth control. Somatic alterations acquired at the level of the cell become fixed in the developing cancer as chromosomal translocations, deletions, inversions, amplifications or point mutations. Since the ultimate unit of susceptibility to carcinogens is at the level of the cell, somatic gene alterations play an important role in carcinogenesis, as all neoplastic tumours exhibit somatic alterations. The incorporation of somatic alterations, such as oncogenes and tumour-suppressor genes, into epidemiological research provides an opportunity to clarify the role of exposure, other genetic changes and prognosis in cancer pathogenesis. The manner in which environmental factors act to initiate, accelerate or retard neoplastic progression Is currently being investigated using somatic gene mutational spectra to identify specific etiological carcinogens. Exploring the relationships between germline and somatic alterations may help to identify the timing of genetic events, important etiological exposures and gene-gene epistatic phenomena. Examining somatic alterations within the context of carcinogen-metabolizing enzymes may elucidate specific carcinogenic mechanisms. The use of somatic alterations to predict prognoses for patients with various malignancies may also help to enhance our ability to define subgroups of patients with different disease courses and treatment responses.

Prognostic significance of p53, PCNA, and c-erbB-2 in endometrial enocarcinoma.

Previous studies of oncogenes, tumor suppressor genes, and proliferation markers in endometrial adenocarcinoma have obtained conflicting results regarding the usefulness of these markers in predicting prognosis. This study examined p53, PCNA, and c-erbB-2 immunohistochemically to clarify the relationship of these markers to each other and to FIGO stage, myometrial invasion, and survival. We studied 64 cases of endometrial carcinoma, treated between 1988 and 1995, for overexpression of p53, percentage of PCNA expression (PCNA index), and c-erbB-2 cytoplasmic membrane staining. Thirty-two percent of tumors expressed p53, 39% displayed a PCNA index of > = 25%, and 69% expressed c-erbB-2. p53 overexpression was significantly associated with stage (p=0.027), PCNA index > = 25% (p=0.005), c-erbB-2 expression (p=0.018), and vital status (p=0.04). PCNA index > = 25% was associated with stage (p=0.008), myometrial invasion (p=0.008), and c-erbB-2 expression (p=0.05), and weakly associated with vital status (p=0.07). No associations were observed for c-erbB-2 with stage, invasion, or vital status. There was some suggestion of a decreased survival in patients whose tumors overexpressed p53 (Log Rank; p=0.09) or had a PCNA index > = 25% (Log Rank; p=0.13). Additional, larger studies are needed to evaluate the prognostic value of PCNA and p53 expression in endometrial adenocarcinoma.

Expression of the hyaluronan receptor, CD44S, in epithelial ovarian cancer is an independent predictor of survival.

Most ovarian carcinomas present at advanced stage, principally as the result of dissemination to peritoneal sites. Standard CD44 (CD44S) is the principal receptor for hyaluronic acid, and in vitro and animal studies have suggested that the attachment of ovarian carcinoma cells to the peritoneal mesothelium involves the interaction between CD44S on ovarian carcinoma cells and hyaluronic acid on mesothelial surfaces. We, therefore, analyzed a series of ovarian carcinomas for the expression of CD44S by immunohistochemistry to see whether expression of this receptor by tumor cells correlated with clinicopathological factors and measures of patient outcome. Fifty-six fixed, paraffin-embedded primary epithelial ovarian tumors were immunostained with antibody to CD44S. Membrane staining was considered positive, and results were correlated with stage, grade, age, histology, and survival. Twenty-two (39%) tumors were positive for CD44S. There was no correlation between CD44 expression and histological type, grade, age, or stage. However, CD44 expression was significantly associated with survival in both univariate (P = 0.003) and multivariate (P = 0.006) analyses. These results support a role for CD44S expression in the spread of ovarian epithelial cancer and suggest that expression of this molecule is a significant independent predictor of survival in women with this disease.

Incidence of colorectal carcinoma in the U.S.: an update of trends by gender, race, age, subsite, and stage, 1975-1994.

BACKGROUND: Colon carcinoma incidence rates have risen sharply over the second half of this century, particularly among males and blacks. In the late 1970s, incidence rates among whites began to decline for distant disease. Approximately 10 years later regional disease rates began to fall. The decline in incidence rates among whites largely has been attributed to more widespread colorectal carcinoma screening. However, similar trends by stage in blacks have not been observed. METHODS: The incidence of colorectal carcinoma was evaluated by race, gender, age, and stage of disease for each subsite using data from > 220,000 cases diagnosed between 1975 and 1994 in the U. S. Surveillance, Epidemiology, and End Results program. RESULTS: Recent data have continued to show a decrease in incidence rates of total colorectal carcinoma in whites since the mid-1980s, particularly for the distal colon and rectum. Overall, proximal colon carcinoma rates were higher than distal colon or rectal carcinoma rates throughout the study period. Proximal colon carcinoma rates in blacks were considerably higher than in whites and continued to increase, whereas rates in whites showed signs of declining. The age-specific and stage-specific trends for proximal colon carcinoma in blacks were not consistent with the possibility of earlier disease detection through screening. CONCLUSIONS: Etiologic studies are necessary to understand the large increases in the incidence of proximal colon carcinoma among blacks.

Prevalence of pedigrees suggestive of hereditary nonpolyposis colorectal cancer among a community sample of women eligible for screening mammography.

OBJECTIVE: To determine from a large cohort of women eligible for screening mammography, the number who would meet criteria for genetic testing for hereditary nonpolyposis colorectal cancer (HNPCC). METHODS: Detailed personal and family cancer histories, obtained from 6,682 women aged 50-80 years randomly selected from communities in Washington State, were matched to the Amsterdam criteria, Bethesda guidelines, and Japanese criteria for HNPCC. RESULTS: One (0.015%) respondent met the Amsterdam criteria, 2 (0.035%) met the Japanese criteria and 5 (0.075%) met the Bethesda guidelines. CONCLUSION: Using the time of presentation for initial mammography as an opportunity to screen for HNPCC would detect very few families at high risk for this condition.

Allelic deletion analysis of the FHIT gene predicts poor survival in non-small cell lung cancer.

The fragile histidine triad (FHIT) gene at chromosome 3p14.2 is a candidate tumor suppressor gene linked to cancers of the lung, breast, colon, pancreas, and head and neck. Reports of frequent allelic deletion and abnormal transcripts in primary lung tumors plus recent evidence that it is targeted by tobacco smoke carcinogens suggest that it plays an important role in lung carcinogenesis. Non-small cell lung carcinoma still maintains a poor 5-year survival rate with the stage of disease at presentation as a major determinant of prognosis. We examined for allelic deletion at the FHIT locus in a series of 106 non-small cell lung carcinomas for which a full clinical, epidemiological, and 5-year survival profile was available. We found an allelic deletion frequency of 38% at one or two intragenic microsatellites. Allelic deletion of FHIT was related to tumor histology with 4 of 20 adenocarcinomas (20%) displaying loss of heterozygosity (LOH) compared with 12 of 22 (55%) nonadenocarcinomas (P = 0.03). We found that 63% of tumors with LOH of FHIT also had p53 missense mutations whereas only 26% with LOH had wild type p53 negative sequence (P = 0.02). We also found a significant trend toward poorer survival in patients with LOH of at least one locus of the FHIT gene (log rank, P = 0.01). This survival correlation is independent of tumor stage, size, histological subtype, degree of differentiation, and p53 mutation status. Our data support the hypothesis that the loss of the FHIT contributes to the molecular pathogenesis of human lung cancer and is an indicator of poor prognosis.

p21waf1/cip1 and transforming growth factor beta 1 protein expression correlate with survival in non-small cell lung cancer.

p21waf1/cip1 encodes a cyclin-dependent kinase inhibitor that is transcriptionally activated by the p53 tumor suppressor gene, transforming growth factor beta 1 (TGF-beta 1), AP2, and other pathways. Because p21waf1/cip1, p53, and TGF-beta 1 all regulate apoptosis and the cell cycle, we tested the hypothesis that their relative protein levels would correlate with biological features including the survival of non-small cell lung cancer (NSCLC) patients. We conducted an immunohistochemical analysis of p21waf1/cip1 and TGF-beta 1 and identified four patient groups with distinct survival outcomes. Concordant p21waf1/cip1 and TGF-beta 1 expression (i.e., either high p21waf1/cip1 and high TGF-beta 1 expression or low p21waf1/cip1 and low TGF-beta 1 expression) predicted 70% disease-free survival at 2000 days of follow-up. Discordant p21waf1/cip1 and TGF-beta 1 expression (i.e., either high p21waf1/cip1 and low TGF-beta 1 expression or low p21waf1/cip1 and high TGF-beta 1 expression) predicted 35% disease-free survival (P = 0.0003; log-rank test). These survival relationships were not attributable to differences in grade, stage, or p53 status. Although current models do not fully explain these complex interactions, most of these data fit a paradigm whereby TGF-beta 1 regulation determines NSCLC survival. In addition to the survival correlation, we found that high p21waf1/cip1 protein expression correlated with high tumor grade (P = 0.014). There is little evidence that p21waf1/cip1 protein levels accurately predict p53 mutation status in NSCLC; specifically, 20 of 48 (42%) tumors with p53 mutations contained high levels of p21waf1/cip1 protein. These findings indicate that p21waf1/cip1 immunohistochemical analysis may provide useful information concerning the biological properties of NSCLC.

Aspirin use and p53 expression in colorectal cancer.

p53 protein overexpression indicates loss of tumor suppressor activity and is the most common genetic alteration in colorectal neoplasms. Epidemiologic and experimental studies suggest that regular use of aspirin may reduce colorectal cancer risk. We set out to determine whether p53 overexpression of the colorectum was associated with a patient's history of aspirin use. Self-administered questionnaires, including information on aspirin use, were obtained from 163 patients with nonfamilial colorectal cancer and from 326 healthy controls. Nuclear p53 protein overexpression using anti-p53 CM-1 polyclonal antibody was observed in 44.8% (73/163) of patients' tumors. A nonsignificant inverse association was observed between use of aspirin and colorectal cancer. Compared with that for nonusers, the odds ratio (OR) for individuals who took aspirin at least twice weekly was 0.68 (95% confidence interval [95% CI]: 0.39-1.18). The odds ratio for those individuals who used aspirin for less than 5 years was 0.54 (95% CI: 0.24-1.23), and 0.80 (95% CI: 0.42-1.51) for those who used aspirin for 5 years or more, when compared with nonusers. An inverse association of regular aspirin use (two times per week or more) was found both for cases with p53 overexpression (OR: 0.79; 95% CI: 0.39-1.59), and for cases without p53 overexpression (OR: 0.56; 95% CI: 0.25-1.22). There was little evidence of a difference in the effect of aspirin use on cancer risk between cases with and without p53 overexpression, even after adjustment for potential confounders.

Bcl-2 immunohistochemistry in a surgical series of non-small cell lung cancer patients.

The bcl-2 gene is implicated in oncogenesis by its ability to prolong cell survival through the inhibition of apoptosis, without increasing cell proliferation. An association between immunohistochemical staining for bcl-2 protein and the histological type and prognosis of non-small cell carcinoma was hypothesized by Pezzella et al. (N Engl J Med 329:690-694, 1993). In a case series, we stained formalin-fixed, paraffin-embedded tumor tissue from 106 surgical non-small cell lung cancer patients with an antibody to bcl-2 protein (DAKO clone 124, Carpinteria, CA). The resulting bcl-2 staining data were evaluated for associations with demographic, histological, immunohistochemical, and genetic features, including p53 mutations. Bcl-2 staining was observed in tumors from 29 of 106 (27%) of subjects, but was significantly less frequent in subjects' adenocarcinoma histology (8 of 55, 14.6%) (P = .007). This finding persisted after adjustment for age, gender, stage, grade, smoking history, and disease-free survival. In univariate analyses, no association was seen with age, weight, body mass index, gender, or pack-years smoking; tumor grade, stage, or patient performance status; p53 or c-erbB2 immunohistochemical staining, or p53 mutations. These data agree with earlier reports that bcl-2 staining is less common in adenocarcinomas; however, our data do not support the hypothesis that bcl-2 staining confers a better prognosis overall, in squamous cell carcinoma, or in an older patient population.

Oral contraceptives, reproductive factors and p53 gene expression in colorectal cancer.

Protective effects of oral contraceptives and high parity on the development of colorectal cancer have been hypothesized. However, the epidemiological data are inconsistent. This inconsistency may be due in part to the biological heterogeneity of colorectal tumors. A recent investigation of hepatocellular carcinoma demonstrated an association between lack of p53 expression and oral contraceptive use. We investigated the relationship between oral contraceptive use and other reproductive factors with p53 over-expression in 64 post-menopausal women, 45-86 years of age, with non-familial colorectal adenocarcinoma. Fifty per cent (32/64) of colorectal tumors displayed nuclear over-expression of p53 protein. Women with a history of oral contraceptive use were significantly less likely to have p53 positive (+) tumors than women who never used oral contraceptives (P = 0.02). In contrast, tumors from women who had never been pregnant were more likely to be p53 + compared to tumors from parous women (P = 0.10). These data suggest that oral contraceptive use and pregnancy are associated with a p53 independent pathway in the development of colorectal cancer.

Methodological issues in the use of tumour markers in cancer epidemiology.

In this chapter, we review major methodological and practical issues associated with the use of tumour markers. At this stage of development, studies with a combination of tumour, susceptibility and exposure markers are needed to illustrate the link between exposure and biological response and to assess the interactive effects of tumour susceptibility markers in this process. Several practical issues related to the application of tumour markers are discussed, including banking of tumour tissue, setting a laboratory strategy and performing etiological heterogeneity analysis.